Resharpening stone tools (IMAGE) Kent State University Caption Metin I. Eren resharpening the stone tools with pressure flaking at the site in Montana (left). He also produced an expedient axe with soft hammer percussion (right). (Images credit: Seth Morris). Credit Seth Morris Usage Restrictions No restrictions License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.